if you have non-steam ESO account, start with 1.
if you have steam account, start with 5.
if you afraid to use your main steam account, start with 7
1. create a steam account registered for Argentina
2. test if your method of payment working, just do a small purchase of anything in steam
3. if its not working just find a way to upload funds on your steam balance, there is many options, World wide steam gift cards for example
4. connect your eso account to steam -
Support | The Elder Scrolls Online
5. if you already have eso steam account, just change your steam store country to argentina
6. during all this steps better to use VPN for Argentina
7. You can create separate steam acc for this and buy basic ESO for it (5 usd argentina price), and then buy crowns and gift various crown store items to your main acc
7.1 Note - you cant gift eso+
8. enjoy very low prices well... for everything
ITS NOT a VIOLATION of any Zenimax/ESO TOS or EULAs, i double checked
however,
its a violation of Steam TOS, but so far i figured out in discords of various guilds, many ppl using this trick without any issues for a long time, probably few years
just do not abuse it, ie do not change country in steam settings back and forth to find other cheap offers every time they available
example:
Just a moment... . Steam Database